Longitudinal changes in plasma sex hormone concentrations correlate with changes in CT-measured regional adiposity among Japanese American men over 10 years.

OBJECTIVE: Ageing in male adults is typically accompanied by adiposity accumulation and changes in circulating sex hormone concentrations. We hypothesized that an ageing-associated increase in oestrogens and decrease in androgens would correlate with an increase in adiposity. DESIGN: 10-year prospective, observational study. STUDY SUBJECTS: A total of 190, community-dwelling men in the Japanese American Community Diabetes Study. MEASUREMENTS: At 0 and 10 years, CT scanning quantified intra-abdominal fat (IAF) and subcutaneous fat (SCF) areas while plasma concentrations of oestradiol, oestrone, testosterone and dihydrotestosterone were measured by liquid chromatography-tandem-mass spectrometry at each time point. Multivariate linear regression analyses assessed correlations between 10-year changes in hormone concentrations and IAF or SCF, adjusting for age and baseline fat depot area. RESULTS: Participants were middle-aged [median 54.8 years, interquartile range (IQR) 39.9-62.8] men and mostly overweight by Asian criterion (median BMI 24.9, IQR 23.3-27.1) and with few exceptions had normal sex-steroid concentrations. Median oestradiol and dihydrotestosterone did not change significantly between 0 and 10 years (P = .084 and P = .596, respectively) while median oestrone increased (P < .001) and testosterone decreased (P < .001). Median IAF and SCF increased from 0 to 10 years (both P < .001). In multivariate analyses, change in oestrone positively correlated (P = .019) while change in testosterone (P = .003) and dihydrotestosterone (P = .014) negatively correlated with change in IAF. Plasma oestradiol and oestrone positively correlated with change in SCF (P = .041 and P = .030, respectively) while testosterone (P = .031) negatively correlated in multivariate analysis. CONCLUSION: Among 190 community-dwelling, Japanese American men, increases in IAF were associated with decreases in plasma androgens and increases in plasma oestrone, but not oestradiol, at 10 years. Further research is necessary to understand whether changing hormone concentrations are causally related to changes in regional adiposity or whether the reverse is true.

HbA1c, fasting and 2 h plasma glucose in current, ex- and never-smokers: a meta-analysis.

AIMS/HYPOTHESIS: The relationships between smoking and glycaemic variables have not been well explored. We compared HbA1c, fasting plasma glucose (FPG) and 2 h plasma glucose (2H-PG) in current, ex- and never-smokers. METHODS: This meta-analysis used individual data from 16,886 men and 18,539 women without known diabetes in 12 DETECT-2 consortium studies and in the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) and Telecom studies. Means of three glycaemic variables in current, ex- and never-smokers were modelled by linear regression, with study as a random factor. The I (2) statistic was used to evaluate heterogeneity among studies. RESULTS: HbA1c was 0.10% (95% CI 0.08, 0.12) (1.1 mmol/mol [0.9, 1.3]) higher in current smokers and 0.03% (0.01, 0.05) (0.3 mmol/mol [0.1, 0.5]) higher in ex-smokers, compared with never-smokers. For FPG, there was no significant difference between current and never-smokers (-0.004 mmol/l [-0.03, 0.02]) but FPG was higher in ex-smokers (0.12 mmol/l [0.09, 0.14]). In comparison with never-smokers, 2H-PG was lower (-0.44 mmol/l [-0.52, -0.37]) in current smokers, with no difference for ex-smokers (0.02 mmol/l [-0.06, 0.09]). There was a large and unexplained heterogeneity among studies, with I (2) always above 50%; I (2) was little changed after stratification by sex and adjustment for age and BMI. In this study population, current smokers had a prevalence of diabetes that was 1.30% higher as screened by HbA1c and 0.52% lower as screened by 2H-PG, in comparison with never-smokers. CONCLUSION/INTERPRETATION: Across this heterogeneous group of studies, current smokers had a higher HbA1c and lower 2H-PG than never-smokers. This will affect the chances of smokers being diagnosed with diabetes.

Plasma amino acid profile, a biomarker for visceral adipose tissue that can substitute for waist circumference in Japanese Americans.

BACKGROUND: Greater visceral fat area (VFA) is associated with cardiometabolic outcomes. We sought to identify cross-sectional and longitudinal associations between amino acid (AA) levels and VFA in Japanese-Americans. METHODS: From the cohort of 342 Japanese-American participants (51% men) in a study of diabetes risk factors who were free from diabetes, we measured levels of 20 AA by mass spectrometry, height, weight, waist circumference (WC), VFA, subcutaneous fat area by single-slice CT at the umbilicus. Using AA significantly associated with VFA in univariate analyses, we created a VFA prediction index, termed the 4A index. We compared area under receiver-operating characteristic curve (AUROC) of the 4A index to WC and an existing AA index (Yamakado et al. Clin Obes 2012) in classifying VFA at different cutoff values. We fit age-adjusted linear regression models to evaluate associations between AA levels and change in VFA over 5 years. RESULTS: All 20 AA levels significantly detected VFA excess, but WC was better. The 4A index performed better than Yamakado index at classifying VFA ≥ 100 cm2 (0.798, 0.807 vs. 0.677, 0.671 for men and women, p < 0.0033) and VFA ≥ sex-specific median values (0.797, 0.786 vs. 0.676, 0.629 for men and women, p < 0.0017). AA significantly associated with change in VFA over 5 years were asparagine, glutamate, glutamine, glycine, methionine, proline, threonine in men; and histidine, isoleucine, tyrosine in women (p < 0.05). CONCLUSIONS: The 4A index can serve as a biomarker for VFA in Japanese-Americans and be considered for this purpose when WC is not available.

Lower High-Density Lipoprotein Cholesterol Concentration Is Independently Associated with Greater Future Accumulation of Intra-Abdominal Fat.

BACKGROUND: Both intra-abdominal fat (IAF) and high-density lipoprotein cholesterol (HDL-C) are known to be associated with cardiometabolic health. We evaluated whether the accumulation of computed tomography (CT)-measured IAF over 5 years was related to baseline HDL-C concentration in a prospective cohort study. METHODS: All participants were Japanese-Americans between the ages of 34 and 74 years. Plasma HDL-C concentration and CT measurements of IAF, abdominal subcutaneous fat (SCF), and thigh SCF cross-sectional areas were assessed at baseline and at 5-year follow-up visits. RESULTS: A total of 397 subjects without diabetes were included. The mean±standard deviation HDL-C concentration was 51.6±13.0 mg/dL in men and 66.0±17.0 mg/dL in women, and the IAF was 91.9±48.4 cm2 in men and 63.1±39.5 cm2 in women. The baseline plasma concentration of HDL-C was inversely associated with the change in IAF over 5 years using multivariable regression analysis with adjustment for age, sex, family history of diabetes, weight change over 5 years, and baseline measurements of body mass index, IAF, abdominal SCF, abdominal circumference, thigh SCF, and homeostatic model assessment for insulin resistance. CONCLUSION: These results demonstrate that HDL-C concentration significantly predicts future accumulation of IAF over 5 years independent of age, sex, insulin sensitivity, and body composition in Japanese-American men and women without diabetes.

Leptin and Adiponectin Concentrations Independently Predict Future Accumulation of Visceral Fat in Nondiabetic Japanese Americans.

OBJECTIVE: Whether leptin and adiponectin are independently associated with regional body fat distribution was investigated in a prospective study of Japanese Americans. METHODS: Nondiabetic participants 39 to 79 years of age were followed for 5 years to assess change in body composition. Leptin and adiponectin concentrations were evaluated at baseline and by single-slice computed tomography measurements of intra-abdominal fat (IAF), abdominal subcutaneous fat (SCF), and thigh SCF cross-sectional areas at baseline and at 5 years. RESULTS: Ninety-six men and ninety-five women without diabetes had the following baseline mean (SD) values: age 45.7 (3.5) years and 46.4 (3.9) years, IAF 78.7 (38.6) cm2 and 62.1 (39.0) cm2 , leptin concentration 4.5 (2.3) µg/L and 10.2 (5.2) µg/L, and adiponectin concentration 7.4 (3.2) µg/mL and 10.8 (4.7) µg/mL, respectively. Baseline leptin (ß = 1.7722, P = 0.014) and adiponectin concentrations (ß = -0.4162, P < 0.001) were significantly associated with IAF change over 5 years in multivariable models adjusting for age, sex, diabetes family history, weight change over 5 years, and baseline measurements of BMI, IAF, abdominal SCF, waist circumference, thigh fat, and homeostatic model assessment of insulin resistance. CONCLUSIONS: In nondiabetic Japanese Americans, a higher concentration of leptin was associated with greater accumulation of IAF and a higher concentration of adiponectin with lesser accumulation of IAF over 5 years.

Comparison of twenty indices of insulin sensitivity in predicting type 2 diabetes in Japanese Americans: The Japanese American Community Diabetes Study.

AIMS: We compared 20 previously reported indices of insulin sensitivity derived from samples during an oral glucose tolerance test (OGTT) to determine which was best in predicting incident type 2 diabetes. METHODS: We prospectively followed 418 Japanese Americans without diabetes for 10-11 years. We compared ability to predict incident diabetes of 20 insulin sensitivity indices-9 based on fasting samples, 7 based on 2-h and/or fasting samples, and 4 based on multiple samples (0, 30, 60, 120 min) during an OGTT-by integrated discrimination improvement, category free net reclassification improvement, and area under the receiver operator characteristic curve. RESULTS: There were 95 incident cases of diabetes. The Cederholm and Gutt indices, requiring more than only fasting samples, were the best to predict incident diabetes as judged by integrated discrimination improvement (0.187, 0.184), category free net reclassification improvement (0.962, 1.030), and area under the receiver operator characteristic curve (0.864, 0.863, respectively). Fasting indices were clearly inferior to both the Cederholm and Gutt indices. CONCLUSIONS: Among the 20 indices, the Cederholm and Gutt indices predicted diabetes best but the Gutt index may be preferable because it requires fewer samples during an OGTT.

Intra-Abdominal Fat and High Density Lipoprotein Cholesterol Are Associated in a Non-Linear Pattern in Japanese-Americans.

BACKGROUND: We describe the association between high density lipoprotein cholesterol (HDL-C) concentration and computed tomography (CT)-measured fat depots. METHODS: We examined the cross-sectional associations between HDL-C concentration and intra-abdominal (IAF), abdominal subcutaneous (SCF), and thigh fat (TF) areas in 641 Japanese-American men and women. IAF, SCF, and TF were measured by CT at the level of the umbilicus and mid-thigh. The associations between fat area measurements and HDL-C were examined using multivariate linear regression analysis adjusting for age, sex, diabetes family history, homeostasis model assessment of insulin resistance (HOMA-IR), and body mass index (BMI). Non-linearity was assessed using fractional polynomials. RESULTS: Mean±standard deviation of HDL-C concentration and IAF in men and women were 1.30±0.34 mg/dL, 105±55.3 cm², and 1.67±0.43 mg/dL, 74.4±46.6 cm² and differed significantly by gender for both comparisons (P<0.001). In univariate analysis, HDL-C concentration was significantly associated with CT-measured fat depots. In multivariate analysis, IAF was significantly and non-linearly associated with HDL-C concentration adjusted for age, sex, BMI, HOMA-IR, SCF, and TF (IAF: ß=-0.1012, P<0.001; IAF²: ß=0.0008, P<0.001). SCF was also negatively and linearly associated with HDL-C (ß=-0.4919, P=0.001). CONCLUSION: HDL-C does not linearly decline with increasing IAF in Japanese-Americans. A more complex pattern better fits this association.

Apolipoprotein B Levels Predict Future Development of Hypertension Independent of Visceral Adiposity and Insulin Sensitivity.

BACKGROUND: High plasma apolipoprotein B (apoB) levels have been shown to be associated with hypertension, central obesity, and insulin resistance in cross-sectional research. However, it is unclear whether apoB levels predict future hypertension independent of body composition and insulin sensitivity. Therefore, we prospectively investigated whether plasma apoB concentrations independently predicted the risk of hypertension in a cohort of Japanese Americans. METHODS: A total of 233 normotensive Japanese Americans (77 men, 156 women; mean age, 46.4±11.0 years) were followed over 10 years to monitor them for the development of hypertension. Fasting plasma concentrations of apoB, glucose, and insulin were measured at baseline. Insulin sensitivity was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). The abdominal visceral and subcutaneous fat areas were measured at baseline using computed tomography. Logistic regression analysis was used to estimate the association between apoB concentrations and the odds of incident hypertension. RESULTS: The 10-year cumulative incidence of hypertension was 21.5%. The baseline apoB level was found to be positively associated with the odds of incident hypertension over 10 years after adjustment for age, sex, body mass index, systolic blood pressure, abdominal visceral fat area, abdominal subcutaneous fat area, total plasma cholesterol concentration, diabetes status, and HOMA-IR at baseline (odds ratio and 95% confidence interval for a 1-standard deviation increase, 1.89 [1.06 to 3.37]; P=0.030). CONCLUSION: Higher apoB concentrations predicted greater risks of future hypertension independent of abdominal visceral fat area and insulin sensitivity in Japanese Americans.

Age at first reproduction and economic change in the context of differing kinship ecologies.

Kinship systems which tend to be based on ecologies of subsistence also assign differential power, privilege, and control to human connections that present pathways for manipulation of resource access and transfer. They can be used in this way to channel resource concentrations in women and hence their reproductive value. Thus, strategic female life course trade-offs and their timing are likely to be responsive to changing preferences for qualities in women as economic conditions change. Female life histories are studied in two ethnic groups with differing kinship systems in NE India where the competitive market economy is now being felt by most households. Patrilineal Bengali (599 women) practice patrilocal residence with village exogamy and matrilineal Khasi (656 women) follow matrilocal residence with village endogamy, both also normatively preferring three-generation extended households. These households have helpful senior women and significantly greater income. Age at first reproduction (AFR), achieved adult growth (height) and educational level (greater than 6 years or less) are examined in reproductive women, ages 16-50. In both groups, women residing normatively are older at AFR and taller than women residing nonnormatively. More education is also associated with senior women. Thus, normative residence may place a woman in the best reproductive location, and those with higher reproductive and productive potential are often chosen as households face competitive market conditions. In both groups residing in favorable reproductive locations is associated with a faster pace of fertility among women, as well as lower offspring mortality among Khasi, to compensate for a later start.

Higher High Density Lipoprotein 2 (HDL2) to Total HDL Cholesterol Ratio Is Associated with a Lower Risk for Incident Hypertension.

BACKGROUND: Recent studies have suggested that high density lipoprotein (HDL) cholesterol is inversely associated with the development of hypertension. We aimed to determine the association between different HDL cholesterol subclasses and risk of future hypertension. METHODS: A total of 270 Japanese Americans (130 men, 140 women) without hypertension between the ages of 34 to 75 years were enrolled. Blood pressure was measured with a mercury sphygmomanometer, and average blood pressure was calculated. Incident hypertension was determined 5 to 6 and 10 to 11 years after enrollment. HDL2, HDL3, and total HDL cholesterol were measured at baseline. RESULTS: During 10 years of follow-up, the cumulative incidence of hypertension was 28.1% (76/270). In univariate analysis, age, diabetes, waist circumference, systolic and diastolic blood pressure, fasting glucose, insulin resistance index, total and low density lipoprotein cholesterol, and visceral adipose tissue were significant predictors for incident hypertension. Among the HDL cholesterol subclass, HDL2 cholesterol was inversely associated with hypertension incidence, but both total and HDL3 cholesterol were not. In addition, HDL2/HDL cholesterol was inversely associated with future hypertension risk. In multivariate analysis, age (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.26 to 2.31; P=0.001), systolic blood pressure (OR, 1.83; 95% CI, 1.31 to 2.56; P<0.001), and HDL2/HDL cholesterol (OR, 0.71; 95% CI, 0.52 to 0.98; P=0.035), were associated with future development of hypertension. CONCLUSION: A higher proportion of HDL2 cholesterol among total HDL cholesterol predicted a lower risk for incident hypertension. However, concentrations of total HDL, HDL2, and HDL3 cholesterol were not independent predictors of incident hypertension.

Change in CT-measured abdominal subcutaneous and visceral but not thigh fat areas predict future insulin sensitivity.

AIMS: We examined the longitudinal association between change in body composition directly measured by computed tomography (CT) and future insulin sensitivity. METHODS: This was a prospective study with 10 years of follow-up with 297 Japanese-American without diabetes. Intra-abdominal fat area (IAFA) and abdominal subcutaneous fat area (SCFA), and thigh SCFA were measured by CT. Insulin sensitivity was calculated by HOMA-IR and the Matsuda index. RESULTS: Baseline and change in IAFA were significantly and independently associated with change in HOMA-IR and Matsuda index during follow-up. In multivariate analysis, IAFA and 10-year change in IAFA (Δ IAFA) was significantly and positively associated with 10-year HOMA-IR (p < 0.001) and significantly and negatively associated with 10-year Matsuda index (p < 0.001). The association with Matsuda index though was non-linear and best modeled as a quadratic function (Δ IAFA +â€¯Δ IAFA2). No significant associations in multivariate analyses were seen between thigh SCFA and insulin sensitivity or abdominal SCFA and HOMA-IR but an increase in abdominal SCFA was associated with diminished insulin sensitivity measured by the Matsuda index. CONCLUSIONS: An increase in visceral adiposity predicts diminished insulin sensitivity over 10 years of follow-up independent of the size of this adipose depot at baseline.

Minimum waist and visceral fat values for identifying Japanese Americans at risk for the metabolic syndrome.

OBJECTIVE: Japanese American is an ethnic group with a high risk for type 2 diabetes, which is linked to the metabolic syndrome. Central adiposity is considered to play a key role in the metabolic syndrome. Not known are the optimal cut point values for central and visceral adiposity to identify Japanese Americans at risk for the metabolic syndrome. RESEARCH DESIGN AND METHODS: Study subjects included 639 Japanese Americans. The nonadipose variables of the metabolic syndrome were defined using modified International Diabetes Federation criteria, and the accuracy of identifying at least two of these by intra-abdominal fat area (IAFA) as measured by computed tomography and waist circumference was cross-sectionally assessed using area under receiver operating characteristic (ROC) curves. The values for IAFA and waist circumference that resulted in maximizing the Youden index were defined as "optimal." RESULTS: The area under the ROC curve for IAFA exceeded that for waist circumference (men 0.787 vs. 0.686; women 0.792 vs. 0.721). For women, the optimal cut points for IAFA and waist circumference were 51.5 cm(2) and 80.8 cm (age < or = 56 years) and 86.3 cm(2) and 89.0 cm (age > 56 years). For men, the optimal cut points for IAFA and waist circumference were 88.6 cm(2) and 90.0 cm (age < or = 57 years) and 96.1 cm(2) and 87.1 cm (age > 57 years). CONCLUSIONS: These results argue that current Japanese waist circumference cut points for the metabolic syndrome need to be revised. Moreover, the waist circumference and IAFA cut points should be age specific, especially in women. Appropriate waist circumference cut points are from 80 to 90 cm in women and from 87 to 90 cm in men.

Change in visceral adiposity is an independent predictor of future arterial pulse pressure.

OBJECTIVES: Pulse pressure (PP), a marker of arterial stiffness, and body composition are both risk factors for cardiovascular disease. Little is known about whether changes in body composition may be linked to future PP. We sought to determine whether change in amount of abdominal and thigh fat over 5 years predicted PP at 10 years. METHODS: Visceral fat as well as abdominal and thigh subcutaneous fat areas were measured by computed tomography at baseline and 5 years later in 284 Japanese Americans (mean age 49.3 years; 50.4% men) without hypertension, heart disease, and glucose-lowering medication use at baseline. PP at 10 years was calculated as the difference between SBP and DBP measured with a mercury sphygmomanometer. The association between change in fat at 5 years and arterial PP at 10 years, adjusted for baseline PP, was examined using linear regression analysis. MAIN RESULTS: Change in abdominal visceral fat area at 5 years was positively associated with 10-year PP independent of sex, 5-year change in BMI, and baseline age, BMI, PP, abdominal visceral fat, smoking status, alcohol consumption, physical activity, homeostasis model assessment insulin resistance, and fasting plasma glucose. There were no significant associations between baseline amounts or change in abdominal or thigh subcutaneous fat areas and future PP. CONCLUSION: The accumulation of abdominal visceral fat over time independently predicted future PP in Japanese Americans.

Association of Thigh Muscle Mass with Insulin Resistance and Incident Type 2 Diabetes Mellitus in Japanese Americans.

BACKGROUND: Skeletal muscle plays a major role in glucose metabolism. We investigated the association between thigh muscle mass, insulin resistance, and incident type 2 diabetes mellitus (T2DM) risk. In addition, we examined the role of body mass index (BMI) as a potential effect modifier in this association. METHODS: This prospective study included 399 Japanese Americans without diabetes (mean age 51.6 years) who at baseline had an estimation of thigh muscle mass by computed tomography and at baseline and after 10 years of follow-up a 75-g oral glucose tolerance test and determination of homeostasis model assessment of insulin resistance (HOMA-IR). We fit regression models to examine the association between thigh muscle area and incidence of T2DM and change in HOMA-IR, both measured over 10 years. RESULTS: Thigh muscle area was inversely associated with future HOMA-IR after adjustment for age, sex, BMI, HOMA-IR, fasting plasma glucose, total abdominal fat area, and thigh subcutaneous fat area at baseline (P=0.033). The 10-year cumulative incidence of T2DM was 22.1%. A statistically significant interaction between thigh muscle area and BMI was observed, i.e., greater thigh muscle area was associated with lower risk of incident T2DM for subjects at lower levels of BMI, but this association diminished at higher BMI levels. CONCLUSION: Thigh muscle mass area was inversely associated with future insulin resistance. Greater thigh muscle area predicts a lower risk of incident T2DM for leaner Japanese Americans.

Predictors of Incident Type 2 Diabetes Mellitus in Japanese Americans with Normal Fasting Glucose Level.

BACKGROUND: Little is known about the natural course of normal fasting glucose (NFG) in Asians and the risk factors for future diabetes. METHODS: A total of 370 Japanese Americans (163 men, 207 women) with NFG levels and no history of diabetes, aged 34 to 75 years, were enrolled. Oral glucose tolerance tests were performed at baseline, 2.5, 5, and 10 years after enrollment. RESULTS: During 10 years of follow-up, 16.1% of participants met criteria for diabetes diagnosis, and 39.6% of subjects still had NFG levels at the time of diabetes diagnosis. During 5 years of follow-up, age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01 to 1.10; P=0.026) and family history of diabetes (OR, 3.24; 95% CI, 1.42 to 7.40; P=0.005) were independently associated with future diabetes diagnosis; however, fasting glucose level was not an independent predictor. During 10 years of follow-up, family history of diabetes (OR, 2.76; 95% CI, 1.37 to 5.54; P=0.004), fasting insulin level (OR, 1.01; 95% CI, 1.00 to 1.02; P=0.037), and fasting glucose level (OR, 3.69; 95% CI, 1.13 to 12.01; P=0.030) were associated with diabetes diagnosis independent of conventional risk factors for diabetes. CONCLUSION: A substantial number of subjects with NFG at baseline still remained in the NFG range at the time of diabetes diagnosis. A family history of diabetes and fasting insulin and glucose levels were associated with diabetes diagnosis during 10 years of follow-up; however, fasting glucose level was not associated with diabetes risk within the relatively short-term follow-up period of 5 years in subjects with NFG.

Predictors of Incident Type 2 Diabetes Mellitus in Japanese Americans with Normal Fasting Glucose Level.

BACKGROUND: Little is known about the natural course of normal fasting glucose (NFG) in Asians and the risk factors for future diabetes. METHODS: A total of 370 Japanese Americans (163 men, 207 women) with NFG levels and no history of diabetes, aged 34 to 75 years, were enrolled. Oral glucose tolerance tests were performed at baseline, 2.5, 5, and 10 years after enrollment. RESULTS: During 10 years of follow-up, 16.1% of participants met criteria for diabetes diagnosis, and 39.6% of subjects still had NFG levels at the time of diabetes diagnosis. During 5 years of follow-up, age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01 to 1.10; P=0.026) and family history of diabetes (OR, 3.24; 95% CI, 1.42 to 7.40; P=0.005) were independently associated with future diabetes diagnosis; however, fasting glucose level was not an independent predictor. During 10 years of follow-up, family history of diabetes (OR, 2.76; 95% CI, 1.37 to 5.54; P=0.004), fasting insulin level (OR, 1.01; 95% CI, 1.00 to 1.02; P=0.037), and fasting glucose level (OR, 3.69; 95% CI, 1.13 to 12.01; P=0.030) were associated with diabetes diagnosis independent of conventional risk factors for diabetes. CONCLUSION: A substantial number of subjects with NFG at baseline still remained in the NFG range at the time of diabetes diagnosis. A family history of diabetes and fasting insulin and glucose levels were associated with diabetes diagnosis during 10 years of follow-up; however, fasting glucose level was not associated with diabetes risk within the relatively short-term follow-up period of 5 years in subjects with NFG.

Natural history of impaired glucose tolerance in Japanese Americans: Change in visceral adiposity is associated with remission from impaired glucose tolerance to normal glucose tolerance.

AIMS: To describe the roles of intra-abdominal fat and its change in the remission of impaired glucose tolerance (IGT) to normal glucose tolerance (NGT). METHODS: We followed 157 Japanese Americans with IGT at baseline for 10-11 years without external intervention. We measured intra-abdominal and abdominal subcutaneous fat area (IAFA and ASFA) by computed tomography at baseline and at 5-6 years of follow-up. Change in IAFA and ASFA (ΔIAFA and ΔASFA) were calculated by subtracting baseline fat area from 5-6 year follow-up fat area. Glucose and insulin at fasting and during a 75-g oral glucose tolerance test, insulinogenic index (IGI [Δinsulin/Δglucose (30-0 min)]) and homeostasis model assessment for insulin resistance (HOMA-IR) were measured at baseline. RESULTS: Fourty-four subjects remitted to NGT. Among those with lower IAFA (≤median 91.31 cm2) and the lowest tertile of ΔIAFA, 45% remitted, while with higher IAFA (>91.31 cm2) and the highest tertile of ΔIAFA, only 12.5% remitted. ΔIAFA was significantly associated with remission to NGT (multiple-adjusted odd ratio [1-SD decrease] 1.93, 95% CI 1.10-3.36) independent of IAFA, ASFA, ΔASFA, IGI, HOMA-IR, age, sex, and family history of diabetes. CONCLUSIONS: In the natural history of IGT, change in intra-abdominal fat was associated with remission to NGT.

Design and validation of a novel estimator of visceral adipose tissue area and comparison to existing adiposity surrogates.

AIMS: Visceral adiposity measured by computed tomography (CT) as intra-abdominal fat area (IAFA) predicts metabolic diseases. Existing adiposity surrogates have not been systematically compared to a regression-based model derived in individuals of Japanese ancestry. We developed and validated a method to estimate IAFA in individuals of Japanese ancestry and compared it to existing adiposity surrogates. METHODS: We assessed age, BMI, waist circumference (WC), fasting lipids, glucose, smoking status, grip strength, mid-thigh circumference (MTC), humeral length, leg length, and IAFA by single-slice CT at the umbilicus for 622 Japanese Americans. We used stepwise linear regression to predict IAFA and termed the predicted value the Estimate of Visceral Adipose Tissue Area (EVA). For men, the final model included age, BMI, WC, high-density lipoprotein cholesterol (HDLc), glucose, and MTC; for women, age, BMI, WC, HDLc, low-density lipoprotein cholesterol, glucose, and MTC. We compared goodness-of-fit (R2) from linear regression models and mean-squared errors (MSE) from k-fold cross-validation to compare the ability of EVA to estimate IAFA compared to an estimate by Després et al., waist-to-height ratio, WC, deep abdominal adipose tissue index, BMI, lipid accumulation product, and visceral adiposity index (VAI). We classified low/high IAFA using area under receiver-operating characteristic curves (AUROC) for IAFA dichotomized at the 75th percentile. RESULTS: EVA gave the least MSE and greatest R2 (men: 1244, 0.61; women: 581, 0.72). VAI gave the greatest MSE and smallest R2 (mean 2888, 0.08; women 1734, 0.14). CONCLUSIONS: EVA better predicts IAFA in Japanese-American men and women compared to existing surrogates for adiposity.

Measuring dietary acculturation in Japanese Americans with the use of confirmatory factor analysis of food-frequency data.

BACKGROUND: Epidemiologic evidence suggests that dietary changes associated with acculturation to a Western diet may increase the risk of type 2 diabetes in Japanese Americans. OBJECTIVE: We hypothesized that dietary acculturation patterns could be measured by confirmatory factor analysis (CFA) by using a culturally sensitive food-frequency questionnaire (FFQ). We examined the utility of the estimated factor scores by testing for associations with diabetes and 2 risk factors for diabetes-body mass index (BMI; in kg/m(2)) and C-reactive protein (CRP). DESIGN: By using cross-sectional data from a sample of 219 Nisei (second-generation Japanese American; mean age 70 y) and 277 Sansei (third-generation Japanese American; mean age 42 y) participants in the Japanese American Family Study, we conducted CFA on 5 items characteristic of a Japanese diet and 4 items characteristic of a Western diet. The resulting factor scores were examined for associations with diabetes by using logistic regression and for associations with BMI and CRP by using linear regression. RESULTS: CFA confirmed the presence of Japanese and Western food factors. The Nisei had a significantly higher average factor score for the Japanese food factor and significantly lower average factor score for the Western food factor than did the Sansei. In Sansei persons, but not in Nisei persons, the Western food factor score was significantly associated with plasma CRP concentration (P = 0.02), BMI (P = 0.02), and diabetes (P = 0.001). CONCLUSIONS: In this Japanese American sample, dietary acculturation can be estimated by using CFA on FFQ data. Future studies should investigate the effects of dietary acculturation on disease risk independent of other lifestyle factors.

Superiority of the Modification of Diet in Renal Disease equation over the Cockcroft-Gault equation in screening for impaired kidney function in Japanese Americans.

The Cockcroft-Gault and the Modification of Diet in Renal Disease (MDRD) Study equations have not been validated in Asian Americans with varying degrees of glucose tolerance. We compared both equations to 24-h urinary creatinine clearance, the latter as a standard measurement of glomerular filtration rate (GFR), in 398 Japanese Americans (62.1+/-5.8 years, mean+/-S.D.) who had normal glucose tolerance (NGT) (n=138), impaired glucose tolerance (IGT) (n=136) and diabetes (n=124). Although both the Cockcroft-Gault (r=0.65, P<0.001) and the MDRD (r=0.74, P<0.001) equations correlated well with creatinine clearance, the latter was significantly superior (P=0.013 between r values). Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) for the MDRD equation was significantly greater than for the Cockcroft-Gault equation (AUC 0.86 versus 0.80, P=0.015) in classifying subjects as having mildly reduced GFR (<90ml/min per 1.73m(2)). However, both equations overestimated the number of individuals with decreased GFR. We conclude therefore that while the MDRD equation more accurately identifies Asians who are in the early stages of kidney disease, as for other groups, a correction term appears necessary in order to reduce the number of Asian subjects being falsely diagnosed with CKD.